/*
 * [New BSD License]
 * Copyright (c) 2011-2012, Brackit Project Team <info@brackit.org>  
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Brackit Project Team nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.brackit.xquery.function.fn;

import org.brackit.xquery.ErrorCode;
import org.brackit.xquery.QueryContext;
import org.brackit.xquery.QueryException;
import org.brackit.xquery.atomic.Bool;
import org.brackit.xquery.atomic.QNm;
import org.brackit.xquery.atomic.Str;
import org.brackit.xquery.function.AbstractFunction;
import org.brackit.xquery.module.StaticContext;
import org.brackit.xquery.xdm.Sequence;
import org.brackit.xquery.xdm.Signature;

/**
 * 
 * @author Sebastian Baechle
 * 
 */
public class SubstringMatch extends AbstractFunction {
	public enum Mode {
		CONTAINS, STARTS_WITH, ENDS_WITH
	};

	private final Mode mode;

	public SubstringMatch(QNm name, Mode mode, Signature signature) {
		super(name, signature, true);
		this.mode = mode;
	}

	@Override
	public Sequence execute(StaticContext sctx, QueryContext ctx, Sequence[] args)
			throws QueryException {
		if (args.length == 3) {
			Str collation = (Str) args[2];

			if (!collation.str
					.equals("http://www.w3.org/2005/xpath-functions/collation/codepoint")) {
				throw new QueryException(ErrorCode.ERR_UNSUPPORTED_COLLATION,
						"Unsupported collation: %s", collation);
			}
		}

		String str = (args[0] != null) ? ((Str) args[0]).stringValue() : "";
		String pattern = (args[1] != null) ? ((Str) args[1]).stringValue() : "";

		if (pattern.isEmpty()) {
			return Bool.TRUE;
		}
		if (str.isEmpty()) {
			return Bool.FALSE;
		}

		switch (mode) {
		case CONTAINS:
			return (str.contains(pattern)) ? Bool.TRUE : Bool.FALSE;
		case STARTS_WITH:
			return (str.startsWith(pattern)) ? Bool.TRUE : Bool.FALSE;
		case ENDS_WITH:
			return (str.endsWith(pattern)) ? Bool.TRUE : Bool.FALSE;
		default:
			throw new QueryException(ErrorCode.BIT_DYN_RT_ILLEGAL_STATE_ERROR);
		}
	}
}